Conventional solid soap compositions intended for personal use usually have a major proportion by weight of salts of longer chain, i.e. C.sub.16 and above, monocarboxylic acids and a minor proportion by weight of salts of shorter chain, i.e. C.sub.14 and below, monocarboxylic acids. A typical soap composition intended for personal use will contain between about 55% and 80% of C.sub.16 and above salts and between about 45% and 20% of C.sub.14 and below salts. Usually the C.sub.16 and above salts will form at least about 60% by weight of the soap content and more usually at least about 70% by weight.
The feedstocks which provide the long chain monocarboxylic acids may be obtained from natural sources i.e. fats and oils, or synthetic sources, e.g. oxidation of paraffins. However, the natural sources form by far the larger feedstock proportion. Fats and oils from plants, animal and marine sources are used throughout the world in proportions depending on the local conditions of supply and the economy. The shorter chain length materials are acknowledged as the components providing the lather generated during use and a common source of these components is coconut oil. This oil is in wide demand for soap making and, despite the considerable world production, its price is consistently above those for the other soap making fats and oils, in particular those providing the C.sub.16 and above chain lengths. These cost considerations are general to any lauric source oil.
Soap makers have in the past given considerable attention to the possibility of replacing some or all of the coconut derived acids by other, more economic, materials while retaining the properties associated with the coconut derived materials. Examples of disclosures already present in the literature are UK Nos. 1281895, 1295275, 1314604 and 1287895 (Unilever).